This regulator is included with the HAZMAT Oxylator Resuscitation Kit utilized by all the Office of Homeland Defense National Medical Response Teams (NMRTs), many Metropolitan Medical Response Systems (MMRSs), and National Guard WMD / CSTs. In a mass casualty situation resulting from a chemical inhalation, it provides a back-up SCBA tank option to operate the Oxylator EMX or Oxylator EM-100 patient ventilation device when O2 tank sources are depleted or not readily replenished. With an additional coupler, the SCBA regulator can then be attached to a scuba tank for additional back-up operation.